WBI 개발 적용을 통한 교수-학습이 수학과 학업성취 신장에 미치는 영향 : 중학교 1학년 함수단원을 중심으로 Focusing on the Unit 'Function' in the 1st grade of Middle School

김응환,오정학 한국학교수학회 2001 韓國學校數學會論文集 Vol.4 No.2

The teaching-learning method utilizing Web makes it possible for the students take the initiative in any field and offers the teaching strategy, methodology and teaching-learning materials suitable for students' ability and standard. The purpose of this study is to investigate the characteristics of WBI in mathematics class for the effective teaching and learning focusing on the unit 'Function' in the 1st grade of middle school and verify its effectiveness by developing the WBI programs which can progress learning achievement and applying them to math class. Two hypotheses were established for this study. Hypothesis 1 : There will be meaningful difference between the group that studies under WBI and the one that doesn't. Hypothesis 2: There will be meaningful difference in the attitude and interest toward learning between the group that studies under WBI and the one that doesn't. In order to find out the result, I have made a comparative analysis through t-verification on the object of two classes of the 1st grade in P middle school that I have been working for. The result shows that the class utilizing WBI is more effective than the traditional lecture-oriented class , since there is a meaningful difference between the control group and experimental one and also that the class based on WEB has a great influence on students' interest and positive attitude toward math class.

해양 갈조류를 생물흡착제로 이용한 납흡착 특성 연구

서정호,감상규,오영희,이동환,이민규 동의대학교 기초과학연구소 1998 基礎科學硏究論文集 Vol.8 No.1

Lead sorption performances by biomass of nonliving, dried marine brown algae Undaria pinnatifida, Hizikia fusiformis, and Sargassum fulvellum used as biosorbent materials were investigated. As the amount of biosorbent materials added was increased, the lead removal by biosorbent materials increased but the lead biosorption capacities decreased. However, with increasing initial lead concentration the lead biosorption capacities by the biosorbent materials increased but lead removal efficiencies decreased. In the range of initial lead concentration(C_0) 10-500 mg/L the lead biosorption capacities and removal efficiencies by the biosorbent materials increased with increasing pH. Among the biosorbent materials used in this study, the lead biosorption capacities decreased in the following sequence: U. pinnatifida $gt; H. fusiformis $gt; S. fulvellum. The lead biosorption by biosorbent materials were expressed by the Langmuir isotherm better than the Freundlich isotherm. The biosorption rate could be expressed by the first order reaction rate equation for initial lead concentration like that r_ad = 0.288C_0 for U. pinnatifida, r_ad = 0.255C_0 for H. fusiformis, and r_ad = 0.161C_0 for S. fulvellum.

Galvanic Replacement Reactions in Metal Oxide Nanocrystals

Oh, Myoung Hwan,Yu, Taekyung,Yu, Seung-Ho,Lim, Byungkwon,Ko, Kyung-Tae,Willinger, Marc-Georg,Seo, Dong-Hwa,Kim, Byung Hyo,Cho, Min Gee,Park, Jae-Hoon,Kang, Kisuk,Sung, Yung-Eun,Pinna, Nicola,Hyeon, Ta American Association for the Advancement of Scienc 2013 Science Vol.340 No.6135

<P><B>Hollowing Out Metal Oxide Nanoparticles</B></P><P>Corrosion is normally a problem, but it can be useful, for example, when you wish to create hollow metal nanoparticles, whereby the reduction of one metal species in solution drives the dissolution of the core of the particle. <B>Oh <I>et al.</I></B> (p. 964; see the Perspective by <B>Ibáñez and Cabot</B>) adapted this approach to metal oxide nanoparticles by placing Mn<SUB>3</SUB>O<SUB>4</SUB> nanocrystals in solution with Fe<SUP>2+</SUP> ions, which replaces the nanocrystal exterior with γ-Fe<SUB>2</SUB>O<SUB>3</SUB>. At sufficiently high Fe<SUP>2+</SUP> concentrations, hollow γ-Fe<SUB>2</SUB>O<SUB>3</SUB> nanocages formed. These hollow structures could be used as anode materials for lithium ion batteries.</P>

音素間 類似度의 整數空間에의 投影에 依한 單語音聲의 認識

오영환(Yung Hwan Oh) 한국정보과학회 1983 정보과학회논문지 Vol.10 No.4

音素認識部를 包含하는 單語音聲認識시스템의 機能을 向上시키기 爲한 方法으로, 音素間 類似度의 整數空間에의 投影을 提案하고 本 認識시스템에 依한 컴퓨터 시뮬레이션 結果에 關해서도 記述했다. 提案된 手法은 從來의 音素記號列의 패턴整合에 依한 認識에 比해 良好한 結果를 얻었다. To improve word speech recognition system including phoneme recognizer, a transform method which maps similarity between phonemes into integer space is proposed In this paper. Computer simulation with Korean digits speech are earned out, and good results are obtained comparing with traditional method which directly uses phoneme code strings

3. 주로 formant 주파수에 의한 숫자음의 음소인식에 대하여

오영환(OH, Yung-Hwan) 대한전자공학회 1981 대한전자공학회 학술대회 Vol.1981 No.8

단어 음성의 시점 · 종점 결정 및 유성 · 무성 · 무음 분류 알고리즘

오영환(Yung Hwan Oh) 한국정보과학회 1985 정보과학회논문지 Vol.12 No.1

본 논문에서는 단어음성의 시점 · 종점 결정 및 유성 · 무성 · 무음분류를 할 수 있는 비교적 간단한 알고리즘의 개발을 위해, 각 자음을 포함하는 25개의 단어음성을 대상으로 한 컴퓨터 시믈레이션 결과에 대해 논했다. 대수에너지, 영교차률, 일표본지연 자기상관계수를 특징 파라미터로 사용한 결과, 알고리즘의 복잡도에 비해 비교적 좋은 결과를 얻을 수 있었다. In this paper, a comparatively simple algorithm for endpoints determination and voiced-unvoiced-silence classification, and its simulation results for 25 spoken words are shown. Log energy, zero crossing rate and one-sample delayed autocorrelation coefficient are used as feature parameters and promising results are obtained considering the complexity of the algorithm.

Identification of Hybrids using SSR markers from Polyembryonic Citrus Breeding Lines

Sun-Yung Yoon,Hyo-Min Ahn,Hyun-Jeong Oh,Kyung-Hwan Boo,Ho-Bang Kim,Gyoeng-Lyong Jeon 한국육종학회 2015 한국육종학회 심포지엄 Vol.2015 No.07

Polyembryony in many citrus varieties is an impediment in breeding because it makes hard to identify hybrids after crossbreeding. So, it has become imperative for developing efficient methods to distinguish zygotic seedling generated from polyembryonic seed depending on citrus variety. Simple sequence repeat(SSR) marker is one of useful systems for such purpose. However, SSR markers to separate zygotic seedlings derived from the crossbreeding between ‘Marita unshiu’ (Citrus unshiu) ‘Seongjeon’ and ‘Shiranuhi mandarin’ [(C. unshiu x C. sinensis) x C. reticulata] ‘Hallabong’ have not been developed yet. In this study we tried to identify an effective SSR marker to screen zygotic seedling after crossbreeding between ‘Seongjeon’ and ‘Hallabong’. For this investigation, 387 seedlings were generated from 114 seeds produced from crossing those two varieties. A total of 116 SSR markers were tested to identify a special marker for distinguishing origin, zygotic or nucellar seedling. As a result, two markers, SSR012 and SSR093, were found to be more effective than other markers. These two SSR markers might be useful to select zygotic individuals in crossbreeing between ‘Seongjeon’ and ‘Hallabong’.

多母集團間 判別分析에 의한 音素識別 및 그의 應用

오영환(Yung Hwan Oh) 한국정보과학회 1982 정보과학회논문지 Vol.9 No.2

本 論文에서는 線形豫測分析時 얻어지는 音響파라미터인 自己相關係數, 線形豫測係數 및 偏自己相關係數를 利用하여, 多母集團間 判別分析手法에 의한 音素認識過程을 包含하는 單語認識시스템에 대해 論했다. 또한 시스템의 有效性을 確認하기 위해 國語數字音聲을 利用하여 音素認識實驗을 遂行한 結果에 대해서도 記述했다. 이는, 周波數領域의 파라미터나 2母集團間 判別分析手法을 利用하는 認識機에 比해 計算時間과 記憶容量의 節減을 가져 올 수 있다. In this paper, a Korean word-speech recognition system is described, which includes phoneme recognizer using 'multipopulational' discriminant analysis method. Three acoustic parameters used here are autocorrelation coefficients, linear predictive coefficients and partial autocorrelation coefficients obtained from LPC analysis of speech. Results of phoneme recognition experiment with digits speech are also shown. The system can save memory space and calculation time compared with that using formant frequencies or discriminant analysis between two populations.

대화음성의 문형에 기반한 의도분석

송창환(Chang-Hwan Song),최환진(Hwan-Jin Choi),오영환(Yung-Hwan Oh) 한국정보과학회 1995 한국정보과학회 학술발표논문집 Vol.22 No.2A

음성언어 시스템의 구현을 위해서는 음성인식된 결과로부터 대화처리를 위한 효과적인 의도 결정 방법이 필요하다. 본 연구에서는 화자의 의도를 분석하는 방법으로 3가지 통계적인 방법을 제안하고 실험하였다. 첫째는, 의도에 따라 문장을 구성하는 단어가 달라지므로 단어와 의도 사이의 상관값을 계산하여 화자의 의도를 분석하는 방법이다. 둘째는, 출현하는 단어와 어순을 함께 고려하는 방법으로 마르코프 모델을 이용한 의도 그래프(MIG; Markov intention graph)를 학습하여 문장의 의도를 분석하였다. 셋째는, 문장을 이루는 요소들을 4가지 항목을 분류하여 문장을 분석하고 도표 형태로 학습시키는 의도결정도표(IDT; intention decision table)를 정의하여 의도 분석에 사용하였다. 모의 대화를 통하여 수집된 문장들을 15개의 의도로 분류하고, 학습 자료에 나타나는 단어들을 기반으로 단어범주를 정의하였다. 제안된 3가지 방법은 수집된 학습 문장들을 통하여 통계치를 얻었으며 텍스트 문장을 입력으로 하는 실험에 대하여 비교 실험한 결과 IDT를 사용하는 방법이 가장 좋은 결과를 보였다.

Development of engineered Escherichia coli whole-cell biocatalysts for high-level conversion of L-lysine into cadaverine.

Oh, Young Hoon,Kang, Kyoung-Hee,Kwon, Mi Jeong,Choi, Jae Woo,Joo, Jeong Chan,Lee, Seung Hwan,Yang, Yung-Hun,Song, Bong Keun,Kim, Il-Kwon,Yoon, Ki-Hoon,Park, Kyungmoon,Park, Si Jae Published by Stockton Press on behalf of the Socie 2015 Journal of industrial microbiology & biotechnology Vol.42 No.11

<P>A whole-cell biocatalytic system for the production of cadaverine from L-lysine has been developed. Among the investigated lysine decarboxylases from different microorganisms, Escherichia coli LdcC showed the best performance on cadaverine synthesis when E. coli XL1-Blue was used as the host strain. Six different strains of E. coli expressing E. coli LdcC were investigated and recombinant E. coli XL1-Blue, BL21(DE3) and W were chosen for further investigation since they showed higher conversion yield of lysine into cadaverine. The effects of substrate pH, substrate concentrations, buffering conditions, and biocatalyst concentrations have been investigated. Finally, recombinant E. coli XL1-Blue concentrated to an OD600 of 50, converted 192.6??g/L (1317??mM) of crude lysine solution, obtained from an actual lysine manufacturing process, to 133.7??g/L (1308??mM) of cadaverine with a molar yield of 99.90??%. The whole-cell biocatalytic system described herein is expected to be applicable to the development of industrial bionylon production process.</P>